Struct riscv_emu_rust::mmu::Mmu

pub struct Mmu { /* fields omitted */ }

Emulates Memory Management Unit. It holds the Main memory and peripheral devices, maps address to them, and accesses them depending on address. It also manages virtual-physical address translation and memoty protection. It may also be said Bus. @TODO: Memory protection is not implemented yet. We should support.

Implementations

impl Mmu

pub fn new(xlen: Xlen, terminal: Box<dyn Terminal>) -> Self

Creates a new Mmu.

Arguments

• xlen
• terminal

pub fn update_xlen(&mut self, xlen: Xlen)

Updates XLEN, 32-bit or 64-bit

Arguments

• xlen

pub fn init_memory(&mut self, capacity: u64)

Initializes Main memory. This method is expected to be called only once.

Arguments

• capacity

pub fn init_disk(&mut self, data: Vec<u8>)

Initializes Virtio block disk. This method is expected to be called only once.

Arguments

• data Filesystem binary content

pub fn init_dtb(&mut self, data: Vec<u8>)

Overrides defalut Device tree configuration.

Arguments

• data DTB binary content

pub fn tick(&mut self, mip: &mut u64)

Runs one cycle of MMU and peripheral devices.

pub fn update_addressing_mode(&mut self, new_addressing_mode: AddressingMode)

Updates addressing mode

Arguments

• new_addressing_mode

pub fn update_privilege_mode(&mut self, mode: PrivilegeMode)

Updates privilege mode

Arguments

• mode

pub fn update_ppn(&mut self, ppn: u64)

Updates PPN used for address translation

Arguments

• ppn

pub fn fetch_word(&mut self, v_address: u64) -> Result<u32, Trap>

Fetches instruction four bytes. This method takes virtual address and translates into physical address inside.

Arguments

• v_address Virtual address

pub fn load(&mut self, v_address: u64) -> Result<u8, Trap>

Loads an byte. This method takes virtual address and translates into physical address inside.

Arguments

• v_address Virtual address

pub fn load_halfword(&mut self, v_address: u64) -> Result<u16, Trap>

Loads two bytes. This method takes virtual address and translates into physical address inside.

Arguments

• v_address Virtual address

pub fn load_word(&mut self, v_address: u64) -> Result<u32, Trap>

Loads four bytes. This method takes virtual address and translates into physical address inside.

Arguments

• v_address Virtual address

pub fn load_doubleword(&mut self, v_address: u64) -> Result<u64, Trap>

Loads eight bytes. This method takes virtual address and translates into physical address inside.

Arguments

• v_address Virtual address

pub fn store(&mut self, v_address: u64, value: u8) -> Result<(), Trap>

Store an byte. This method takes virtual address and translates into physical address inside.

Arguments

• v_address Virtual address
• value

pub fn store_halfword(&mut self, v_address: u64, value: u16) -> Result<(), Trap>

Stores two bytes. This method takes virtual address and translates into physical address inside.

Arguments

• v_address Virtual address
• value data written

pub fn store_word(&mut self, v_address: u64, value: u32) -> Result<(), Trap>

Stores four bytes. This method takes virtual address and translates into physical address inside.

Arguments

• v_address Virtual address
• value data written

pub fn store_doubleword(
    &mut self,
    v_address: u64,
    value: u64
) -> Result<(), Trap>

Stores eight bytes. This method takes virtual address and translates into physical address inside.

Arguments

• v_address Virtual address
• value data written

pub fn load_word_raw(&mut self, p_address: u64) -> u32

Loads four bytes from main memory or peripheral devices depending on physical address.

Arguments

• p_address Physical address

pub fn store_raw(&mut self, p_address: u64, value: u8)

Stores a byte to main memory or peripheral devices depending on physical address.

Arguments

• p_address Physical address
• value data written

pub fn validate_address(&mut self, v_address: u64) -> Result<bool, ()>

Checks if passed virtual address is valid (pointing a certain device) or not. This method can return page fault trap.

Arguments

• v_address Virtual address

pub fn get_clint(&self) -> &Clint

Returns immutable reference to Clint.

pub fn get_mut_clint(&mut self) -> &mut Clint

Returns mutable reference to Clint.

pub fn get_mut_uart(&mut self) -> &mut Uart

Returns mutable reference to Uart.